Red Hat Application Server: JOnAS User Guide | ||
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The JORAM runtime by default is launched collocated with the JOnAS server (see http://jonas.objectweb.org/current/doc/PG_JmsGuide.html#Running). However, in this configuration the JORAM lifetime is bound to the JOnAS lifetime. If the local JOnAS process terminates, so will the local JORAM. For reliability it is preferable to separate the JOnAS and JORAM processes, especially as a collocated JORAM server is by default non-persistent.
The simplest configuration to separate JOnAS and JORAM, once they are non-collocated, is to create one JORAM instance on one machine in the system, and to couple all JOnAS instances to that one JORAM. However, this is also failure-prone as, if that one JORAM instance quits, all the JOnAS instances will lose their connection—and will not reconnect afterwards!
Hence, the preferred solution is to have one JOnAS instance and one JORAM instance on each participating server. The JORAM instances must then be configured to communicate with each other. Then each JOnAS instance must be configured to connect to its local JORAM instance. This provides the greatest degree of recoverability, given that the JORAM instances are run in persistent mode (mode providing message persistence and thus, guarantee of delivery even in case of a server crash).